Prevalence and Grading of Rotator Cuff and Labral Injuries in Shoulder Pain and Instability using MRI: ACross-sectional Study

Abstract

Introduction: Shoulder joint is a highly mobile joint but is prone for rotator cuff injuries and dislocations. It is necessary to accurately diagnose rotator cuff and labral injuries so that appropriate plan of action for treatment can be taken. Magnetic Resonance Imaging (MRI) can be used to diagnose and describe the extent of rotator cuff tendon and labral injuries and any secondary rotator cuff muscle abnormalities. Aim: To study the demographic profile of patients presenting with shoulder pain and instability, identify the various rotator cuff injuries causing shoulder pain, identify the rotator cuff interval lesions causing microinstability, identify the various labral and bony pathologies in instability, describe the MRI features of the rotator cuff, rotator cuff interval, labral and bony injuries. Materials and Methods: This study was a cross-sectional study of patients with symptoms of either shoulder pain or instability who underwent MRI evaluation of the shoulder in the Department of Radiodiagnosis, Rajarajeswari Medical College and Hospital, Bengaluru, Karnataka, India, from July 2018 to December 2020. The study population consisted of 54 patients with either shoulder pain or instability who underwent MRI of shoulder. All the MRI scans of the shoulder in this study were performed using 1.5 Tesla Siemens Magnetom Avanto (Tim 76x18) MR machine using a flex coil. Results: The study population consisted of 54 patients comprising of 38 males and 16 females. The age of the patients ranged from 20-77 years. Majority of the patients were older than 50 years constituting about 33.33% of the total study population. Rotator cuff injury was the commonest cause of pain. Tendinosis was the commonest type of rotator cuff injury followed by partial-thickness and full-thickness tendon tears. The commonest grade of tendinosis was mild or grade 1. Supraspinatus tendon was the most commonly affected tendon followed by subscapularis and infraspinatus tendons. Teres minor tendon was normal in all the cases. Anterior instability was the commonest type of instability with equal prevalence of soft tissue Bankart, bony Bankart and Perthes lesions. Biceps pulley lesions resulted in long head of biceps tendon instability, microinstability and internal impingement. Conclusion: Rotator cuff injuries are the commonest cause of shoulder pain and are seen more frequently after the fifth decade. Shoulder instability is most commonly seen in young male adults. Tendinosis is the commonest type of rotator cuff injury. Supraspinatus tendon is the most commonly injured tendon. Anterior instability is the commonest type of shoulder instability. Biceps pulley lesions result in long head of biceps tendon instability, microinstability and internal impingement. MRI can diagnose interstitial or intrasubstance tendon tears which are not visualised on arthroscopy. MRI description of tendon and labral tears, tendon retraction and muscle atrophy can guide the orthopaedician during arthroscopy and in treatmentplanning.